Rob Brigham schrieb:
Modern plastics are actually very good at many tasks, and blindly thinking metal is better for everything IS an old-fashioned view as Brad says.
Not better for everything. Just better for the better lenses and cameras....
While I suspect that Brad's comment was pure speculation, I am certain you are wrong that weight is the only advantage to plasics. I thought impact absorbtion was better for one. When plastic is deformed slightly it is more likely to return to its original shape than metal.
Maybe so. But where there is a dent on a metal filter tread like on the
old A20 that I acquired recently, this can easily be repaired, whereas a
plastic one completely cracks like on the a FA28-80/f3.5-4.7 which I
possessed, and which had only 50% of its filter thread. The rest was
completely gone.
What I would like to add it that build is not just about maerials though, but also fit and finish. How big are the gaps between parts, how fliud is the movement, how much play is there in the lens barrel and the focussing ring?
I completely agree. E.g. The K or A24/f2.8 are built better than the
FA*24/f2, and the FA20-35/f4 is built way better than the
FA28-80/f3.5-4.7. Plain F lenses have less play than plain FA lenses,
etc.... But are there plastic Pentax lenses that have better build than
the metal ones?
You really need to handle a lens to assess its build - materials and textbooks don't tell the whole story. I would suggest Brad handles a 77ltd or even the FA*24 and see for himself what the difference in build is. The first time you hold the 77 is a real awakening. Warning though - you will HAVe to obtain one by any means after holding it!
True!
Arnold
